//窗口显示才加载
var wrapTop = $(".digital").offset().top;
var istrue = true;
$(window).on("scroll",
    function() {
        var s = $(window).scrollTop();
        if (s > wrapTop - 500 && istrue) {
            $(".timer").each(count);
            function count(a) {
                var b = $(this);
                a = $.extend({},
                    a || {},
                    b.data("countToOptions") || {});
                b.countTo(a)
            };
            istrue = false;
        };
    })
//设置计数
$.fn.countTo = function (options) {
    options = options || {};
    return $(this).each(function () {
        //当前元素的选项
        var settings = $.extend({}, $.fn.countTo.defaults, {
            from:            $(this).data('from'),
            to:              $(this).data('to'),
            speed:           $(this).data('speed'),
            refreshInterval: $(this).data('refresh-interval'),
            decimals:        $(this).data('decimals')
        }, options);
        //更新值
        var loops = Math.ceil(settings.speed / settings.refreshInterval),
            increment = (settings.to - settings.from) / loops;
        //更改应用和变量
        var self = this,
            $self = $(this),
            loopCount = 0,
            value = settings.from,
            data = $self.data('countTo') || {};
        $self.data('countTo', data);
        //如果有间断，找到并清除
        if (data.interval) {
            clearInterval(data.interval);
        };
        data.interval = setInterval(updateTimer, settings.refreshInterval);
        //初始化起始值
        render(value);
        function updateTimer() {
            value += increment;
            loopCount++;
            render(value);
            if (typeof(settings.onUpdate) == 'function') {
                settings.onUpdate.call(self, value);
            }
            if (loopCount >= loops) {
                //移出间隔
                $self.removeData('countTo');
                clearInterval(data.interval);
                value = settings.to;
                if (typeof(settings.onComplete) == 'function') {
                    settings.onComplete.call(self, value);
                }
            }
        }
        function render(value) {
            var formattedValue = settings.formatter.call(self, value, settings);
            $self.html(formattedValue);
        }
    });
};
$.fn.countTo.defaults={
    from:0,               //数字开始的值
    to:0,                 //数字结束的值
    speed:1000,           //设置步长的时间
    refreshInterval:100,  //隔间值
    decimals:0,           //显示小位数
    formatter: formatter, //渲染之前格式化
    onUpdate:null,        //每次更新前的回调方法
    onComplete:null       //完成更新的回调方法
};
function formatter(value, settings){
    return value.toFixed(settings.decimals);
}
//自定义格式
$('.count-number').data('countToOptions',{
    formmatter:function(value, options){
        return value.toFixed(options.decimals).replace(/\B(?=(?:\d{3})+(?!\d))/g, ',');
    }
});
//定时器
$('.timer').each(count);
function count(options){
    var $this=$(this);
    options=$.extend({}, options||{}, $this.data('countToOptions')||{});
    $this.countTo(options);
}